期刊文献+
共找到34,809篇文章
< 1 2 250 >
每页显示 20 50 100
The First Verification Test of Space-Ground Collaborative Intelligence via Cloud-Native Satellites
1
作者 Wang Shangguang Zhang Qiyang +2 位作者 Xing Ruolin Qi Fei Xu Mengwei 《China Communications》 SCIE CSCD 2024年第4期208-217,共10页
Recent advancements in satellite technologies and the declining cost of access to space have led to the emergence of large satellite constellations in Low Earth Orbit(LEO).However,these constellations often rely on be... Recent advancements in satellite technologies and the declining cost of access to space have led to the emergence of large satellite constellations in Low Earth Orbit(LEO).However,these constellations often rely on bent-pipe architecture,resulting in high communication costs.Existing onboard inference architectures suffer from limitations in terms of low accuracy and inflexibility in the deployment and management of in-orbit applications.To address these challenges,we propose a cloud-native-based satellite design specifically tailored for Earth Observation tasks,enabling diverse computing paradigms.In this work,we present a case study of a satellite-ground collaborative inference system deployed in the Tiansuan constellation,demonstrating a remarkable 50%accuracy improvement and a substantial 90%data reduction.Our work sheds light on in-orbit energy,where in-orbit computing accounts for 17%of the total onboard energy consumption.Our approach represents a significant advancement of cloud-native satellite,aiming to enhance the accuracy of in-orbit computing while simultaneously reducing communication cost. 展开更多
关键词 cloud-native satellite orbital edge computing satellite inference verification test
下载PDF
Recent Progress of Earth Observation Satellites in China
2
作者 HUANG Shusong QI Wenping +3 位作者 ZHANG Shuai XIA Tian WANG Jingqiao ZENG Yong 《空间科学学报》 CAS CSCD 北大核心 2024年第4期731-740,共10页
Currently,China has 32 Earth observation satellites in orbit.The satellites can provide various data such as optical,multispectral,infrared,and radar.The spatial resolution of China Earth observation satellites ranges... Currently,China has 32 Earth observation satellites in orbit.The satellites can provide various data such as optical,multispectral,infrared,and radar.The spatial resolution of China Earth observation satellites ranges from low to medium to high.The satellites possess the capability to observe across multiple spectral bands,under all weather conditions,and at all times.The data of China Earth observation satellites has been widely used in fields such as natural resource detection,environmental monitoring and protection,disaster prevention and reduction,urban planning and mapping,agricultural and forestry surveys,land survey and geological prospecting,and ocean forecasting,achieving huge social benefits.This article introduces the recent progress of Earth observation satellites in China since 2022,especially the satellite operation,data archiving,data distribution and data coverage. 展开更多
关键词 China Earth Observation satellites Satellite operation Data archiving Data distribution Data coverage
下载PDF
Performance evaluation of HY-2 series satellites in marine gravity field recovery
3
作者 Ruijie Hao Xiaoyun Wan Keyan Zhang 《Geodesy and Geodynamics》 EI CSCD 2024年第4期397-403,共7页
China has successfully launched four Haiyang-2(HY-2)series altimetry satellites.HY-2A has attracted significant attention in gravity field recovery,but the performance of other HY-2 series satellites,including HY-2B/C... China has successfully launched four Haiyang-2(HY-2)series altimetry satellites.HY-2A has attracted significant attention in gravity field recovery,but the performance of other HY-2 series satellites,including HY-2B/C/D,is seldom discussed.This study evaluated the performance of all the HY-2 series satellites in recovering marine gravity field.First,the crossover discrepancies in sea surface height of the four satellites,HY-2A,HY-2B,HY-2C,and HY-2D,were analyzed to assess their altimetry stability.It was found that HY-2B had the best altimetry quality,followed by HY-2D.Subsequently,different combina-tions of altimetry data were used to calculate vertical deflections and gravity anomalies in the South China Sea(112°E-119°E,12°N-20°N).The results showed that combining data from HY-2B,HY-2C,and HY-2D improved the inversion accuracy of gravity anomalies by 0.3 mGal compared to using HY-2A data alone.HY-2C and HY-2D contributed to enhancing the accuracy of the east component of vertical deflections. 展开更多
关键词 Satellite altimetry HY-2 Sea surfaceheight Marinegravityfield
下载PDF
Networking Observation and Applications of Chinese Ocean Satellites
4
作者 ZOU Bin LIU Yuxin 《空间科学学报》 CAS CSCD 北大核心 2024年第4期722-730,共9页
This paper presents the networking observation capabilities of Chinese ocean satellites and their diverse applications in ocean disaster prevention,ecological monitoring,and resource development.Since the inaugural la... This paper presents the networking observation capabilities of Chinese ocean satellites and their diverse applications in ocean disaster prevention,ecological monitoring,and resource development.Since the inaugural launch in 2002,China has achieved substantial advancements in ocean satellite technology,forming an observation system composed of the HY-1,HY-2,and HY-3 series satellites.These satellites are integral to global ocean environmental monitoring due to their high resolution,extensive coverage,and frequent observations.Looking forward,China aims to further enhance and expand its ocean satellite capabilities through ongoing projects to support global environmental protection and sustainable development. 展开更多
关键词 Chinese ocean satellites Networking observation Ocean forecasting Ocean disaster prevention and mitigation Ocean ecological monitoring Ocean resource development Polar monitoring Terrestrial applications
下载PDF
搭载实践十号卫星的不同小麦品种突变体鉴定与分析
5
作者 张福彦 李浩 +5 位作者 陈晓杰 王嘉欢 程仲杰 赵婉 范家霖 张建伟 《核农学报》 CAS 北大核心 2025年第1期1-9,共9页
为探讨卫星搭载对小麦农艺性状、高分子量麦谷蛋白亚基(HMW-GS)和分子水平变异的影响,本研究利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)技术、简单重复序列(SSR)标记技术对实践十号返回式科学实验卫星搭载周麦18、周麦22和汶农1... 为探讨卫星搭载对小麦农艺性状、高分子量麦谷蛋白亚基(HMW-GS)和分子水平变异的影响,本研究利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)技术、简单重复序列(SSR)标记技术对实践十号返回式科学实验卫星搭载周麦18、周麦22和汶农14小麦品种干种子的SP3代农艺性状变异和SP5代突变系的HMW-GS和SSR分子标记多态性进行鉴定与分析。结果发现,航天诱变SP3代农艺性状与其野生型存在明显差异,且不同小麦品种对太空环境的敏感性不同。航天搭载能够诱发高分子量麦谷蛋白亚基和基因组DNA发生变异,发现3个小麦品种高分子量麦谷蛋白亚基的变异频率分别为2.15%、3.66%和5.21%,其中汶农14突变体HMW-GS亚基变异频率最高。21个SSR分子标记检测结果显示,周麦18和周麦22的航天诱变突变体与其野生型差异标记数量均不超过2个,而汶农14航天诱变的部分突变体与其野生型间差异标记数量较多,且株高和穗型等性状发生了遗传分离。综上,航天诱变使小麦基因组和蛋白组发生变异,所创制的优异特色突变体可为小麦育种的遗传改良和功能基因的研究利用提供丰富的材料基础。 展开更多
关键词 小麦 卫星搭载 突变体 农艺性状 高分子量麦谷蛋白亚基
下载PDF
GYRO BIAS ON-ORBIT CALIBRATION FOR MICRO SATELLITES 被引量:1
6
作者 郁丰 刘建业 熊智 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2007年第4期300-304,共5页
According to gyro application in micro-satellites, a new gyro bias real-time on-orbit calibration technology is presented and it is independent of any other sensors. The approach relies on gyro on-orbit measurements r... According to gyro application in micro-satellites, a new gyro bias real-time on-orbit calibration technology is presented and it is independent of any other sensors. The approach relies on gyro on-orbit measurements restricted by satellite attitude dynamics and estimates the gyro bias generated when the gyro is electrified. Observability of the calibration model is analyzed and applicable conditions of the technology are derived. Simulation results indicate that the calibration algorithm is accurate and robust at gyro sampling rate, and its convergence speed is fast. Within the given attitude dynamics model error, the convergence time is less than 100 s and the convergence accuracy is about 1.0 (°)/h. Calibration performance can meet requirements of spacecraft operations. 展开更多
关键词 on-orbit calibration gyro bias Kalman filter micro satellite
下载PDF
理筋手法调控兔骨骼肌损伤修复中瘢痕形成的作用机制 被引量:1
7
作者 李开颖 魏晓歌 +5 位作者 宋斐 杨楠 赵振宁 王燕 穆静 马惠昇 《中国组织工程研究》 CAS 北大核心 2025年第8期1600-1608,共9页
背景:理筋手法能够促进骨骼肌修复,治疗骨骼肌损伤。但骨骼肌损伤在修复过程中的纤维化形成、瘢痕组织增生等与损伤修复质量密切相关。开展理筋手法对纤维化形成、瘢痕组织增生的调控作用研究,有利于阐述理筋手法提高骨骼肌损伤修复质... 背景:理筋手法能够促进骨骼肌修复,治疗骨骼肌损伤。但骨骼肌损伤在修复过程中的纤维化形成、瘢痕组织增生等与损伤修复质量密切相关。开展理筋手法对纤维化形成、瘢痕组织增生的调控作用研究,有利于阐述理筋手法提高骨骼肌损伤修复质量的相关机制。目的:探索理筋手法提高兔骨骼肌损伤后修复质量的作用机制,为临床治疗提供科学依据。方法:45只健康成年日本大耳白兔随机分为空白组、模型组、理筋组,每组15只。其中模型组和理筋组均进行腓肠肌打击造模;造模后理筋组于第3天开始进行理筋手法干预,1次/d,15 min/次。各组在造模后的第7,14,21天分别处死5只兔进行观察。苏木精-伊红染色法观察腓肠肌形态及炎性细胞量,Masson染色法观察腓肠肌胶原纤维量,ELISA法检测腓肠肌白细胞介素6和白细胞介素10的表达量,Western blot和RT-PCR检测配对盒基因7、成肌分化因子、肌细胞生成素、肌动蛋白α、转化生长因子β1、Ⅰ型胶原蛋白的蛋白及mRNA表达,免疫组织化学法检测Ⅰ型胶原蛋白的表达。结果与结论:①苏木精-伊红染色及Masson染色结果显示,与模型组比较,理筋组各观察点炎性细胞浸润减少,胶原纤维量减少(P<0.01),肌纤维逐渐愈合;②ELISA结果显示,与模型组比较,理筋组白细胞介素6表达持续降低(P<0.05),而白细胞介素10在造模后第7天时升高(P<0.05),随后呈下降趋势(P<0.05);③Western blot和RT-PCR结果显示,与模型组比较,理筋组造模后第14天配对盒基因7、成肌分化因子、肌细胞生成素的蛋白及mRNA表达量均显著升高(P<0.05),而第21天时却较之前下降(P<0.05);理筋组各观察点肌动蛋白α、转化生长因子β1、Ⅰ型胶原蛋白的蛋白及mRNA表达量相较于模型组均显著降低(P<0.05);④免疫组化结果显示,理筋组各观察点Ⅰ型胶原蛋白的表达量相较于模型组均显著降低(P<0.05);⑤结果表明,理筋手法能够通过抑制炎症、促进肌卫星细胞的增殖分化、减少纤维化的生成,从而提高兔骨骼肌损伤的修复质量。 展开更多
关键词 理筋手法 筋伤 骨骼肌损伤 炎症 肌卫星细胞 纤维化 瘢痕组织 修复质量
下载PDF
DUAL QUATERNION CURVE INTERPOLATION ALGORITHM FOR FORMATION SATELLITES 被引量:1
8
作者 李静 王惠南 刘海颖 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第1期90-95,共6页
The traditional algorithms for formation flying satellites treat the satellite position and attitude sepa- rately. A novel algorithm combining satellite attitude with position is proposed. The principal satellite traj... The traditional algorithms for formation flying satellites treat the satellite position and attitude sepa- rately. A novel algorithm combining satellite attitude with position is proposed. The principal satellite trajectory is obtained by dual quaternion interpolation, then the relative position and attitude of the deputy satellite are ob- tained by dual quaternion modeling on the principal satellite. Through above process, relative position and atti- tude are unified. Compared with the orbital parameter and the quaternion methods, the simulation result proves that the algorithm can unify position and attitude, and satisfy the precision requirement of formation flying satel- lites. 展开更多
关键词 formation satellites dual quaternion interpolation algorithm relative position and attitude
下载PDF
基于纳米金Core-satellites等离子体耦合增强效应的汞离子光纤传感器的研究 被引量:2
9
作者 贾朔 边超 +2 位作者 佟建华 孙楫舟 夏善红 《分析化学》 SCIE EI CAS CSCD 北大核心 2017年第6期785-790,共6页
以DNA杂交双链为联接,构建纳米金颗粒Core-satellites结构并激发等离子体耦合增强效应,利用Hg^(2+)可与DNA中胸腺嘧啶T形成T-Hg^(2+)-T特异性结构,研制了用于检测水中Hg^(2+)的局域等离子体共振(LSPR)光纤传感器。待测溶液中的Hg^(2+)... 以DNA杂交双链为联接,构建纳米金颗粒Core-satellites结构并激发等离子体耦合增强效应,利用Hg^(2+)可与DNA中胸腺嘧啶T形成T-Hg^(2+)-T特异性结构,研制了用于检测水中Hg^(2+)的局域等离子体共振(LSPR)光纤传感器。待测溶液中的Hg^(2+)能够引起富含T的DNA单链折叠,抑制DNA杂交反应,降低等离子体耦合强度,改变LSPR谐振波长。通过检测谐振波长红移变化,实现对Hg^(2+)浓度的定量检测。本方法检测Hg^(2+)的线性范围为5~150 nmol/L,检出限为3.4 nmol/L(3σ)。Zn^(2+)、Mg^(2+)、Pb^(2+)等重金属离子对Hg^(2+)检测无明显干扰作用。实际水样中Hg^(2+)加样回收率为94.2%~105.4%,相对标准偏差<4.8%。 展开更多
关键词 局域等离子体共振 纳米金Core-satellites结构 脱氧核糖核酸 汞离子 光纤传感器
下载PDF
SphK1/S1P/S1PR2信号通路促进肌生成:运动改善骨骼肌健康的新视角
10
作者 张文华 李荀 +3 位作者 张伟超 李欣颖 马帼澳 王孝强 《中国组织工程研究》 CAS 北大核心 2025年第6期1265-1275,共11页
背景:近年来,运动改善骨骼肌的健康已成为学者们关注的一个重要研究内容,适宜的运动对骨骼肌具有积极的作用,其中在运动激活鞘氨醇激酶1(sphingosine kinase1,SphK1)/鞘氨醇-1-磷酸(sphingosine-1-phosphate,S1P)/鞘氨醇-1-磷酸受体2(sp... 背景:近年来,运动改善骨骼肌的健康已成为学者们关注的一个重要研究内容,适宜的运动对骨骼肌具有积极的作用,其中在运动激活鞘氨醇激酶1(sphingosine kinase1,SphK1)/鞘氨醇-1-磷酸(sphingosine-1-phosphate,S1P)/鞘氨醇-1-磷酸受体2(sphingosine-1-phosphate receptor2,S1PR2)信号通路如何改善骨骼肌的健康,正受到科研人员的重视。目的:研究运动经SphK1/S1P/S1PR2信号通路如何改善骨骼肌的健康,探索治疗相关肌肉疾病的新方法,以改善人的骨骼肌健康。方法:检索Web of Science、PubMed、中国知网、万方和维普数据库从建库至今与文章主题相关的文献,以“signaling pathway,SphK1,S1P,S1PR2,skeletal muscle,satellite cell,myogenesis,exercise”为英文检索词,以“信号通路,SphK1,S1P,S1PR2,骨骼肌,卫星细胞,肌生成,运动”为中文检索词,最终纳入69篇文献进行分析。结果与结论:①SphK1/S1P/S1PR2信号通路是一个复杂的调控网络,通过SphK1催化产生的S1P,与S1PR2等受体的相互作用,触发下游信号转导过程,进而调控细胞、组织、器官和系统的多种生物学功能。②SphK1/S1P/S1PR2信号通路能调控卫星细胞增殖和成肌细胞分化,改善肌生成。③文章通过文献资料调研法分析了SphK1/S1P/S1PR2信号通路的生理基础以及运动对其影响的可能性。急性有氧运动可提高骨骼肌中SphK1的表达,人体和动物研究中已证实急性和长期运动均可提高骨骼肌中S1P水平,另外研究表明长期抗阻运动可提高S1PR2在骨骼肌中的表达,部分实验结果表明急性和长期运动对肌肉或者血液中S1P水平无显著影响,出现不同结果的原因可能是选择的研究对象、方式、强度及频率不同,而具体机制尚不明确。④研究认为,运动能够促进SphK1/S1P/S1PR2信号通路在骨骼肌中的表达,调控下游相关信号通路,并且针对这一信号通路的研究可能为骨骼肌疾病的治疗提供新的策略和方法,从而改善骨骼肌健康。⑤未来应深化对SphK1/S1P/S1PR2信号通路与骨骼肌健康关联的研究,进一步揭示其与卫星细胞、成肌细胞的调控关系及与上下游通路的相互作用,挖掘其临床应用价值,制定康复方案时考虑该通路变化,探索不同运动对该通路的影响机制,并将其作为潜在治疗靶点,结合人体肌肉模型提升研究深度和准确性。 展开更多
关键词 SphK1/S1P/S1PR2信号通路 骨骼肌 运动 肌生成 卫星细胞 成肌细胞 机制
下载PDF
利用低轨道卫星地磁观测反演电离层电流概述
11
作者 熊超 王丰珏 +6 位作者 黄宇阳 钱博浩 王思敏 让心怡 宋斯珊 周云良 尹凡 《地球与行星物理论评(中英文)》 2025年第1期45-66,共22页
随着现代卫星技术的发展,携带高精度磁力计的低轨道卫星成为地磁场观测的重要手段,可以提供全球持续的磁场观测,而不受地面和低空天气条件的影响.空间电流,特别是电离层电流,是引起地表和低轨道卫星高度处磁场扰动的主要来源.本文简要... 随着现代卫星技术的发展,携带高精度磁力计的低轨道卫星成为地磁场观测的重要手段,可以提供全球持续的磁场观测,而不受地面和低空天气条件的影响.空间电流,特别是电离层电流,是引起地表和低轨道卫星高度处磁场扰动的主要来源.本文简要介绍了低轨磁测卫星的发展历史和在轨定标流程与方法,回顾了电离层电流的起源、研究历史及产生机制,并详细介绍了利用卫星磁测数据反演电离层不同电流的方法.基于地基和卫星磁测对同一电流的分析结果并不总是一致的,有时会出现明显的差异.造成这些差异的原因可能与采用不同的数据源(比如地基与卫星、卫星与卫星之间)及反演算法中的假设有关.基于有限的观测,在反演中通常要对电流的几何形状和所在位置进行一定的假设,而这些假设可能并不完全满足实际电流的分布.因此,将地基台站和卫星磁测结合起来,通过对比和交叉验证,是检验和改进电离层电流反演算法中假设的合理性的一种有效手段.利用融合后的磁场观测数据,建立更准确的电离层电流反演算法,全面分析电流的形态学和气候学特征,建立以地球磁场信号为媒介的空间天气监测理论与方法,将有助于提升人们对电离层发电机理论、磁层状态以及电离层与磁层之间能量耦合途径等科学问题的理解. 展开更多
关键词 低轨道卫星 星载磁力计 电离层电流反演 太阳静日电流 赤道电集流 场向电流
下载PDF
A Positioning System based on Communication Satellites and the Chinese Area Positioning System(CAPS) 被引量:33
12
作者 Guo-Xiang Ai Hu-Li Shi +6 位作者 Hai-Tao Wu Yi-Hua Yan Yu-Jing Bian Yong-Hui Hu Zhi-Gang Li Ji Guo Xian-De Cai 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2008年第6期611-630,共20页
The Chinese Area Positioning System (CAPS) is a positioning system based on satellite communication that is fundamentally different from the 3"G" (GPS, GLONASS and GALILEO) systems. The latter use special-purpos... The Chinese Area Positioning System (CAPS) is a positioning system based on satellite communication that is fundamentally different from the 3"G" (GPS, GLONASS and GALILEO) systems. The latter use special-purpose navigation satellites to broadcast navigation information generated on-board to users, while the CAPS transfers ground-generated navigation information to users via the communication satellite. In order to achieve accurate Positioning, Velocity and Time (PVT), the CAPS employs the following strategies to over- come the three main obstacles caused by using the communication satellite: (a) by real-time following-up frequency stabilization to achieve stable frequency; (b) by using a single carrier in the transponder with 36 MHz band-width to gain sufficient power; (c) by incorporating Decommissioned Geostationary Orbit communication satellite (DGEO), barometric pressure and Inclined Geostationary Orbit communication satellite (IGSO) to achieve the 3-D posi- tioning. Furthermore, the abundant transponders available on DGEO can be used to realize the large capacity of communication as well as the integrated navigation and communication. With the communication functions incorporated, five new functions appear in the CAPS: (1) combination of navigation and communication; (2) combination of navigation and high accu- racy orbit measurement; (3) combination of navigation message and wide/local area differen- tial processing; (4) combination of the switching of satellites, frequencies and codes; and (5) combination of the navigation message and the barometric altimetry. The CAPS is thereby labelled a PVT5C system of high accuracy. In order to validate the working principle and the performance of the CAPS, a trial system was established in the course of two years at a cost of about 20 million dollars. The trial constellation consists of two GEO satellites located at E87.5° and E110.5°, two DGEOs located at E130° and E142°, as well as barometric altimetry as a virtual satellite. Static and dynamic performance tests were completed for the Eastern, the Western, the Northern, the Southern and the Middle regions of China. The evaluation results are as follows: (1) land static test, plane accuracy range: C/A code, 15-25 m; P code, 5-10 meters; altitude accuracy range, 1- m; (2) land dynamic test, plane accuracy range, C/A code, 15-25 m; P code, 8-10m; (3) velocity accuracy, C/A code, 0.13-0.3 m s-1, P code, 0.15-0.17 m s- 1; (4) timing accuracy, C/A code, 160 ns, P code, 13 ns; (5) timing compared accuracy of Two Way Satellite Time and Frequency Transfer (TWSTFT), average accuracy, 0.068 ns; (6) random error of the satellite ranging, 10.7 mm; (7) orbit determination accuracy, better than 2 m. The above stated random error is 1σ error. At present, this system is used as a preliminary operational system and a complete system with 3 GEO, 3 DGEO and 3 IGSO is being established. 展开更多
关键词 astronomy application satellite navigation satellite communication astrometry astronomic technique
下载PDF
Ocean Observation from Haiyang Satellites: 2012–2014 被引量:3
13
作者 JIANG Xingwei LIN Mingsen 《空间科学学报》 CAS CSCD 北大核心 2014年第5期710-720,共11页
During 2012 and 2014, China has two Haiyang(which means ocean in Chinese, referred to as HY) satellites operating normally in space which are HY-1B and HY-2A. HY-1B is an ocean color environment satellite which was la... During 2012 and 2014, China has two Haiyang(which means ocean in Chinese, referred to as HY) satellites operating normally in space which are HY-1B and HY-2A. HY-1B is an ocean color environment satellite which was launched in April 2007 to observe global ocean color and sea surface temperature, and HY-2A is an ocean dynamic environment satellite which was launched in August 2011 to obtain global marine dynamic environment parameters including sea surface height,significant wave height, ocean wind vectors, etc. Ocean observation data provided by HY-1B and HY-2A have been widely used by both domestic and international users in extensive areas such as ocean environment protection, ocean disaster prevention and reduction, marine environment forecast,ocean resource development and management, ocean investigations and scientific researches, etc. 展开更多
关键词 HY-1B HY-2A OCEAN OBSERVATION satellites OCEAN REMOTE SENSING SATELLITE OCEAN applications
下载PDF
Crosstalk among canonical Wnt and Hippo pathway members in skeletal muscle and at the neuromuscular junction
14
作者 Said Hashemolhosseini Lea Gessler 《Neural Regeneration Research》 SCIE CAS 2025年第9期2464-2479,共16页
Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways... Skeletal muscles are essential for locomotion,posture,and metabolic regulation.To understand physiological processes,exercise adaptation,and muscle-related disorders,it is critical to understand the molecular pathways that underlie skeletal muscle function.The process of muscle contra ction,orchestrated by a complex interplay of molecular events,is at the core of skeletal muscle function.Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction.Within muscle fibers,calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force.Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling.The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis.Myogenic regulators coordinate the diffe rentiation of myoblasts into mature muscle fibers.Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability.Seve ral muscle-related diseases,including congenital myasthenic disorders,sarcopenia,muscular dystrophies,and metabolic myopathies,are underpinned by dys regulated molecular pathways in skeletal muscle.Therapeutic interventions aimed at preserving muscle mass and function,enhancing regeneration,and improving metabolic health hold promise by targeting specific molecular pathways.Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway,a critical regulator of myogenesis,muscle regeneration,and metabolic function,and the Hippo signaling pathway.In recent years,more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers,and at the neuromuscular junction.In fact,research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers.In this review,we will summarize and discuss the data on these two pathways,focusing on their concerted action next to their contribution to skeletal muscle biology.However,an in-depth discussion of the noncanonical Wnt pathway,the fibro/a dipogenic precursors,or the mechanosensory aspects of these pathways is not the focus of this review. 展开更多
关键词 canonical Wnt"Wingless-related integration site"pathway beta-catenin(CTNNB1) Hippo pathway MYOGENESIS MYOTUBE neuromuscular junction satellite cell skeletal muscle fiber transcriptional co-activator with PDZ-binding motif(TAZ) T-cell-specific transcription factor/lymphoid enhancer-binding factor(TCF/LEF) TEA domain family member(TEAD) transducin-like enhancer of split(TLE) yes-associated protein 1(YAP1)
下载PDF
FY-3 Meteorological Satellites and the Applications 被引量:2
15
作者 TANG Yunqiu ZHANG Jiashen WANG Jingsong 《空间科学学报》 CAS CSCD 北大核心 2014年第5期703-709,共7页
FY-3 is the second generation polar-orbiting meteorological satellite of China. The first satellite named FY-3A of this series was launched on 27 May 2008. The first operational satellite named FY-3C of this series wa... FY-3 is the second generation polar-orbiting meteorological satellite of China. The first satellite named FY-3A of this series was launched on 27 May 2008. The first operational satellite named FY-3C of this series was launched on 23 September, 2013. The new generation satellites are to provide three-dimensional, quantitative, multi-spectral global remote sensing data under all weather conditions, which will greatly help the operational numerical weather prediction, global climate change research, climate diagnostics and prediction, and natural disaster monitoring. They will also provide help for many other fields such as agriculture, forestry, oceanography and hydrology. With the above-mentioned capability, the FY-3 satellites can make valuable contributions to improving weather forecasts, global natural-disaster and environmental monitoring. 展开更多
关键词 FY-3 satellites Polar-orbiting SATELLITE REMOTE SENSE
下载PDF
Spectral Coexistence between LEO and GEO Satellites by Optimizing Direction Normal of Phased Array Antennas 被引量:14
16
作者 Chen Zhang Jin Jin +1 位作者 Hao Zhang Ting Li 《China Communications》 SCIE CSCD 2018年第6期18-27,共10页
This paper addresses the spectral coexistence between LEO constellation and GEO belt for global distributed earth stations. A specific method is introduced to mitigate the in-line interference by tilting the direction... This paper addresses the spectral coexistence between LEO constellation and GEO belt for global distributed earth stations. A specific method is introduced to mitigate the in-line interference by tilting the direction normal of phased array antennas of LEO satellites, and the optimal direction is found by solving a non-linear programming problem. The simulation results prove that the proposed approach leads to greater link availability while guaranteeing the desired received signal level especially for low-latitude earth stations. 展开更多
关键词 satellite constellation satellite communication spectral coexistence interference mitigation phased array
下载PDF
The output torque estimation of MCMG for agile satellites 被引量:5
17
作者 Jingrui Zhang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第1期141-146,共6页
Studied in this paper are the attitude control law design and the output torque estimation problem of micro control moment gyros (MCMGs) for the agile satellites executing rapid attitude maneuver mission. An algorit... Studied in this paper are the attitude control law design and the output torque estimation problem of micro control moment gyros (MCMGs) for the agile satellites executing rapid attitude maneuver mission. An algorithm is proposed for estimating the output torques and the gimbal angular rates of MCMGs, which can help engineers to choose reasonable size for actuators so that the cost of satellite can be decreased. According to some special maneuver missions, a numerical example of attitude control system for a small satellite with MCMGs in pyramid configuration is studied, and the simulation results validate the proposed estimation algorithm. 展开更多
关键词 Agile satellite Micro control moment gyro Rapid attitude maneuver
下载PDF
Development of Integrated and Intelligent Geodetic and Photogrammetry Satellites with Corresponding Key Technologies 被引量:2
18
作者 Yuanxi YANG Xia REN Jianrong WANG 《Journal of Geodesy and Geoinformation Science》 CSCD 2023年第4期3-12,共10页
Aerospace surveying and mapping has become the main method of global earth observation.It can be divided into the geodetic observation satellites and the topographic surveying satellites according to the disciplines.I... Aerospace surveying and mapping has become the main method of global earth observation.It can be divided into the geodetic observation satellites and the topographic surveying satellites according to the disciplines.In this paper,the geodetic satellites and photographic satellites are introduced respectively.Then,the existing problems in Chinese earth observation satellites are analyzed,and the comprehensive satellite with integrated payloads,the intensive microsatellite constellation and the intelligent observation satellite are proposed as three different development ideas for the future earth observation satellites.The possibility of the three ideas is discussed in detail,as well as the related key technologies. 展开更多
关键词 aerospace surveying and mapping gravity satellite magnetic satellite optical mapping satellite microwave mapping satellite microsatellite networking intelligent satellite observation
下载PDF
Information acquisition technology for small hydropower stations in remote areas based on high-and low-orbit satellites 被引量:3
19
作者 Zanhong Wu Xiangye Chen Guanxian Wu 《Global Energy Interconnection》 EI CAS CSCD 2021年第5期513-519,共7页
With a lack of coverage in private and public power communication networks,especially for collection of information from hydropower stations in remote areas,communication coverage is a significant issue.Satellite comm... With a lack of coverage in private and public power communication networks,especially for collection of information from hydropower stations in remote areas,communication coverage is a significant issue.Satellite communication provides a large coverage area suitable for a variety of services and is less affected by geographical factors;moreover,the costs are independent of the communication distance.This study investigates information acquisition technology for small hydropower stations in remote areas using high-and low-orbit satellites.The information collection needs of small hydropower stations in remote areas are analyzed,and an information acquisition system is designed using high-and low-orbit satellites.For network security protection,network anomaly detection technology based on a support vector machine algorithm is proposed.The effectiveness of information collection was evaluated and verified for small hydropower plants in remote areas.The system provides technical support for“full coverage,full collection,and full monitoring”of the measurement automation information acquisition system. 展开更多
关键词 Small hydropower information collection High-and low-orbit satellite communication Satellite communication security Support vector machine
下载PDF
Arctic multiyear sea ice variability observed from satellites:a review 被引量:4
20
作者 BI Haibo LIANG Yu +7 位作者 WANG Yunhe LIANG Xi ZHANG Zehua DU Tingqin YU Qinglong HUANG Jue KONG Mei HUANG Haijun 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2020年第4期962-984,共23页
In comparison with seasonal sea ice(first-year ice,FY ice),multiyear(MY)sea ice is thicker and has more opportunity to survive through the summer melting seasons.Therefore,the variability of wintertime MY ice plays a ... In comparison with seasonal sea ice(first-year ice,FY ice),multiyear(MY)sea ice is thicker and has more opportunity to survive through the summer melting seasons.Therefore,the variability of wintertime MY ice plays a vital role in modulating the variations in the Arctic sea ice minimum extent during the following summer.As a response,the ice-ocean-atmosphere interactions may be significantly affected by the variations in the MY ice cover.Satellite observations are characterized by their capability to capture the spatiotemporal changes of Arctic sea ice.During the recent decades,many active and passive sensors onboard a variety of satellites(QuikSCAT,ASCAT,SSMIS,ICESat,CryoSat-2,etc.)have been used to monitor the dramatic loss of Arctic MY ice.The main objective of this study is to outline the advances and remaining challenges in monitoring the MY ice changes through the utilization of multiple satellite observations.We summarize the primary satellite data sources that are used to identify MY ice.The methodology to classify MY ice and derive MY ice concentration is reviewed.The interannual variability and trends in the MY ice time series in terms of coverage,thickness,volume,and age composition are evaluated.The potential causes associated with the observed Arctic MY ice loss are outlined,which are primarily related to the export and melting mechanisms.In addition,the causes to the MY ice depletion from the perspective of the oceanic water inflow from Pacific and Atlantic Oceans and the water vapor intrusion,as well as the roles of synoptic weather,are analyzed.The remaining challenges and possible upcoming research subjects in detecting the rapidly changing Arctic MY ice using the combined application of multisource remote sensing techniques are discussed.Moreover,some suggestions for the future application of satellite observations on the investigations of MY ice cover changes are proposed. 展开更多
关键词 multiyear sea ice Arctic Ocean satellite observation
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部